The aim is to create and maintain a central repository to hold all major human genome data except for bulk DNA sequences. The database aims to provide a major service to the worldwide genome and human gene mapping communities by providing ready access to crucial information on a reliable and timely basis. It is intended that the center should engage in synthesis, integration, and editorial control of mapping information of all kinds and should provide an intellectual focus for the interpretation of genomic data. The specific data manipulation issues are as follows: definition of genetic markers such as genes, phenotypes, probes etc., as map objects establishing standards for data representation and nomenclature acquisition of data validation of data maintenance of data The types of data included: genetic markers: genes, pseudogenes, phenotypes, DNA probes, STSs, etc. . marker variations: DNA polymorphisms, mutations genetic maps physical maps literature references These data manipulation issues are met by establishing a distributive editorial network in 3 layers: a central database support group, core editors with responsibilities for data of general importance chromosome editors with responsibilities for data on individual chromosomes Literature review: information from the literature retrieved in support of the functions of the five Core Editors and the Chromosome Editors.